From basic to specialty, and everything in between

Revisiting “Seven chemical separations to change the world”

In an earlier post I covered a recent article published in the journal Nature[1], listing what Georgia Institute of Technology chemical engineers Ryan Lively and David Sholl believe are the top seven industrial chemical purifications with the highest potential to lower energy use, emissions, and pollution at a global scale.

Despite the long-term benefits that implementing these nonthermal separation alternatives can achieve, Lively and Sholl highlight that the need for investment in research and development of the alternative technologies still exists, partly to make them feasible for large-scale industrial applications. They point out that nondistillation approaches to separation, such as those based on molecular size or chemical properties, are undeveloped and may be expensive to scale up. In separating hydrocarbons from crude oil, for example, the challenge is to develop separation materials that can be used at high temperatures and that can handle complex mixes of molecules. For the purification of alkenes, porous carbon membranes are already available that can be used for bulk separation and would reduce the energy intensity of the process threefold. In this case, however, the challenge is scaling up for industrial separation, which would require surface areas bordering one million square meters and the deployment of new manufacturing methods.

The biggest impact of using alternative separation methods tends to be in industries with large sums of installed capital (for example, distillation columns for separating hydrocarbons from crude oil — or separating alkanes from alkenes —in the petrochemical industry). Companies that have made a big investment in installations and equipment may find that it is not economically feasible to discontinue their use in order to reduce energy requirements. These industries also rely on robust processes that are well proven, and they may not be able to assume the risks of introducing new methodologies into mission-critical steps.

This is a difficulty that my company, Compact Membrane Systems, has faced with our membranes to separate alkanes and alkenes. The strategy we have taken[2] includes the following approaches:

Start by applying the new technologies to waste streams where the separation is not currently done, because the traditional, thermal separation method (such as distillation) is not viable. Using alternative technologies like membranes in this situation clearly adds value, while also proving the capabilities of these new methods to make the intended separation.

Communicate clearly the economic benefit gained from using the alternative technology. By making the case for new technologies through metrics that different stakeholders in the organization can easily understand, decision-making in favor of implementing the nontraditional technologies is simplified.

Plan for the long-haul. In a conservative industry with a lot of installed capital, considerable effort is needed to provide cumulative evidence that new technologies are feasible and to identify the areas where their use is economically beneficial for plant operations.

An ideal climate to promote the development and implementation of alternative separation processes may require multiple favorable elements: appropriate incentives for companies to make the switch from reliance on existing capital to the implementation of novel technologies, prioritization of those applications where new technologies are the most economically advantageous for companies, and identification of areas where regulation may encourage the use of alternative separation technologies.